1. Field of the Invention
This invention relates to a system that provides an area warning of an earthquake prior to the arrival of the hazardous ground motion typically associated with earthquakes and of approaching natural disasters that could impact an area. This advanced warning provides time for users to seek shelter and through automated means to reduce property damage as well as injuries and lives lost.
2. Prior Art
An earthquake or other natural disaster such as fires, floods and tornadoes, as presently experienced in regions around the world and throughout all of mankind's history, have not been preceded by any type of advanced specific area warning that could help general populations avoid damage to lives or property. In the past, natural disasters such as fires, floods, tornadoes and hurricanes were sometimes preceded by general warnings of various types that could allow people time to seek shelter or otherwise protect themselves and their property, but the warnings were very general in nature and were transmitted to widely spaced geographic areas with little or no specific information as to the actual area to be impacted. These general warnings also required receiving devices that were in a ready state and to which the users were receptive in order to take some limited form of damage or injury avoidance.
Attempts in the past by recognized experts, to predict or warn of earthquakes have been widely regarded as futile. There was no recognized way to provide reliable advanced warning to a general population in an appropriately specific area of an impending earthquake prior to the strong ground movement normally associated with an earthquake.
Earthquakes are produced by the movement (fault rupture) of earth deep underground caused by a sudden release of accumulated strain energy. The accumulated strain energy is created by continuous deformation of blocks of earth moving in different directions over a long period of time. This sudden release of energy is caused when the two opposing blocks of earth exceed their elastic abilities. This ground movement (slippage) deep in the earth is radiated to the surface in the form of seismic waves. The site of an earthquake is called the focus and the point on the surface directly above the focus is called the epicenter.
The mechanical properties of the earth that seismic waves travel through, quickly organize the waves into two principal types for these purposes. Compression waves, know as primary or "P" waves travel fastest through the earth's crust. Shear waves, also known as secondary or "S" waves, travel more slowly, at about 60% of the speed of "P" waves.
The "S" waves are the waves which cause the shaking ground surface that is typically associated with earthquakes. The "P" waves are usually undetectable by human senses or are merely felt as an initial jolt, but are easily detectable with common devices currently in widespread use today. Both types of waves are routinely detected and recorded by various types of sensors.
Although wave speeds through the earth vary widely with the type of composition, the ratio between the average speed of a "P" wave and its following "S" wave is quite constant. This fact enables commonly used sensors (seismographs, motion detectors, and accelerometers) to map precise locations and relative magnitudes of the strain releases known as earthquakes around the world. These instruments normally detect both "P" waves and "S" waves and are used almost exclusively for retrospective analysis of earthquakes.
Some efforts have been made to utilize existing capability to provide limited warning of an impending earthquake. All previous efforts either fail to provide an appropriate area early warning signal to a general population and concurrent activation of various ancillary safety devices, or fail to reliably detect the earthquake "P" waves that can give the maximum advance warning necessary for general populations to take proper precautions.
The bulk of a general population in high population density areas, would not benefit from existing efforts or existing types of detection products. "P" Wave detectors with audible alarms rely exclusively on human reactions with very small lead time warnings for those closest to the heaviest damage and most in need of advance warning. "P" Wave detectors and warning systems placed in home or public buildings also require on-going maintenance, are subject to random damage and failure, and fail to provide proper relief from false positive warnings. There has been no recognized, reliable method to warn a general population in a specific area of an impending earthquake prior to the ground movement normally associated with an earthquake.
The following U.S. patents are relevant to this process:
______________________________________ 5,200,735 5,184,889 5,142,499 5,075,857 5,101,195 5,078,172 5,019,803 5,001,682 5,001,466 4,998,601 4,908,803 4,978,948 4,956,875 4,841,287 4,815,044 4,789,922 4,764,762 4,764,761 4,649,524 4,607,376 4,594,582 4,484,186 4,359,722 4,330,103 4,297,690 4,296,496 4,296,485 4,269,011 4,166,344 4,086,504 3,949,300 3,886,494 3,866,121 3,865,990 3,864,674 3,742,478 3,739,283 3,636,452 ______________________________________
Additionally, there are reported to be several commercially available products that attempt to detect earthquake "P" waves and sound an audible alarm. These products fall short of the present invention since their ability to warn of an earthquake is severely limited in time and scope. Waiting for earthquake "P" waves to arrive before sounding an alarm, severely limits the time available for the user and automated ancillary devices to take protective action and minimizes the usefulness of those devices.
None of the aforementioned prior art, or any other prior art known to the applicant, discloses an earthquake early warning system utilizing a large regional array of closely spaced detectors, real time signal processing at each local detector station site, a Central Processing Site to provide sophisticated real time and constantly upgraded warnings specifically to general populations of specific geographic areas that need to be warned. Further, no prior art utilizes the electromagnetic spectrum to issue a warning signal to a specific area general population as well as ancillary automated receiving devices for a general population in that area. Furthermore, no prior art known to the applicant provides a maximum interval of time between the warning and the arrival of damaging earthquake "S" waves. Furthermore, no prior art known to the applicant provides this type of specific area earthquake early warning to mobile users in a general population. Furthermore, no prior art known to the applicant provides directional real time, area earthquake early warning to a general population that is correlated with the location, intensity, and magnitude of the earthquake.
Some efforts have been made to utilize existing capability to provide limited warning of other types of impending natural disasters such as fires, floods, tornadoes or hurricanes. All previous efforts fail to provide an appropriate specific area early warning signal to a general population of inhabitants that are most likely to be affected. Further, they fail to provide concurrent activation of various ancillary safety devices or automated equipment and they fail to activate various types of warning devices that are in an inactive mode to give the maximum advance warning necessary for a general population to take proper precautions.
There are several types of commercially available emergency broadcast devices which are continually tuned to a specific frequency and designed to warn of a natural disaster that might affect a large scale geographic area. These systems transmit warnings to large scale geographic areas with boundaries far exceeding a projected area to actually be impacted by a natural disaster. The subsequent multiple "false alarms" to the majority population of users, reduces the warning effectiveness for the users. No prior art known to the applicant has the capability to reduce the geographic scale of the warning to only the general populations of those specific areas reasonably expected to be impacted by the impending natural disaster.
Further, no prior art known to the applicant is designed to transmit an area early warning signal for either earthquakes or other natural disasters to a plethora of receivers that can be activated by the signal if left in an inactive or off position by the users.
Described herein is a novel and advantageous area earthquake early warning system uniquely employing a plurality of earthquake ground motion sensors each equipped with preprogrammed microprocessors, spectrum analyzers, transmitters and receivers to detect, verify and warn of imminent danger from an earthquake to an appropriate specific geographic area with a general population of users. These warnings are timely and provide continually upgraded information on the status of the earthquake to system users to monitor real time information and modify actions of a general population or ancillary equipment based on that information.
System users employ a warning system signal microprocessor/receiver in a wide variety of devices and functions ranging from simple audible warning devices to sophisticated microprocessor/controllers for major systems such as transportation networks, power generation and distribution networks, and warning systems for schools, hospitals and other public buildings. Warning signal receivers may be incorporated into a very wide variety of existing or new devices such as smoke alarms, telephones, pagers, radios, televisions, computers, emergency lighting, elevators, traffic signals, utility systems and public address systems.
Additionally, this same area warning system enables appropriate warnings to be transmitted to a general population of system users in the event of such natural disasters such as fires, floods, hurricanes, tornadoes or other natural disasters. With these types of natural disasters, the area warning system relies on event detection and initial warning instructions from outside sources such as legally designated Public Safety Offices.
As a natural disaster occurs that threatens a specific area as determined by appropriate Public Safety Officials, a continuously transmitted signal is sent by that Public Safety Office 85 to the Central Processing Site (FIG. 13). The information transmitted by the Public Safety Office to the Central Processing Site 80 allows appropriate analysis of the event occurrence in terms of type of danger, direction, timing and other predetermined levels of public danger. Based on this analysis, the Central Processing Site then transmits warning alert signals to the appropriate Local Station Detector Sites which in turn, transmit an appropriate and continuously upgraded warning signal to system users in the specific geographically predetermined area of each Local Station Detector Site. With this system in place, only specific appropriate general populations in specific appropriate geographic areas are warned. This allows all system users in those general populations, a higher level of confidence in the nature of the warning as well as the severity, timing and type of danger that is imminent. This receipt of an advanced warning to a specific area that is likely to be impacted allows users more time to seek shelter, evacuate or take other appropriate actions and thereby reduces the chances of death, injury and property damages. Warning signal receivers would be of similar type and function as receivers used for earthquake warnings and would include but not be limited to smoke alarms, telephones, pagers, radios, televisions, computers, emergency lighting, elevators, traffic signals, utility lines and public address systems.
The continuously upgraded warning signals sent by the Local Station Detector Sites during both Earthquakes and other natural disasters are received by Microprocessor/Receivers which are also designed to be able to turn on power to devices left in an inactive mode, and then relay the warning signals to appropriate electromechanical controlling devices for performance of predetermined actions.
A preferred embodiment of the invention described herein utilizes a plurality of Local Station Detector Sites, equipped with earthquake seismic motion detectors and microprocessors designed to instantaneously provide a profile of existing ground motion to a Central Processing Site in conjunction with further analysis of similar signals from multiple sites. A warning instruction is then transmitted back to all appropriate Local Station Detector sites to initiate transmission of local area warnings to a general population of all users in an appropriate and specific geographic area with minimal possibility of false alarms. Additionally the Central Processing Site has the ability to send continuously upgraded warning signals for other types of disasters for receipt by each appropriate local station detector site. Each appropriate local station detector site then sends a continuously upgraded warning signal to each system user in its local area regarding the characteristics of the disaster. These warnings are initiated by appropriate Public Safety Offices and analyzed by the Central Processing Site for appropriate action.
Although it is contemplated that in preferred embodiments warning signals would be a form of radio frequency signal, virtually any form of radiant energy such as infrared, electromagnetic, light or acoustical energy may be utilized in other embodiments of the invention. Further, each geographic network may have multiple Central Processing Sites which provide immediate or simultaneous backup in the event of site failure for any reason.
The Local Station Detector sites or the Central Processing sites may be readily utilized alone or in conjunction with other sites such as telephone or utility distribution points, freeways road beds, or any other type of secured locations.
The receivers used by the invention to audibly warn users of an impending earthquake may be stationary or mobile. Stationary receivers include stand alone units, existing smoke alarms, radios, televisions or other types of alarm systems or public address systems. Examples of mobile receivers include those contained within a pocket pager, a cellular telephone, a car radio, or other such device.
Such receivers may also be equipped with means to activate various preprogrammed microprocessor equipped ancillary devices to further enhance the safety features of the invention. Examples are command and control of computers, elevators, lighting systems, electrical generation and transmission systems, transportation control systems, natural gas distribution systems and many other like uses.